Diffuser and connector for pressure operated switch



Sept- 29, 1964 J. D. ROBINSON 3,150,676

DIFFUSER AND CONNECTOR FOR PRESSURE OPERATED SWITCH Filed July l5, 1963 JAMES D. RoBlNsoN BY w www ATTORNEY United States PatentOiice 3,l50,676 Patented Sept. 29, 1964 3,150,676 DHFUSER AND CQNNECTR FR PRESSURE OPERATED SWHTCH James D. Robinson, 746 Poplar Ave., Memphis, Tenn. Filed .luiy 15, 1963, Ser. No. 294516 S Claims. (El. 137-1tL2l) This invention relates to devices for introducing a liquid, such as a rinse aid solution, into a stream of another liquid, such as rinse water, flowing in .a pipe. More particularly, the invention relates to a combination diffuser and fluid connection for a pressure operated switch.

One object of the invention is to provide a device to insure the complete mixing of a concentrated solution into a stream of water flowing in a pipe. In commercial dishwashing apparatus, which conventionally includes a reservoir for a concentrated solution which aids in the rinsing of dishes, and a piston pump for forcing the con centrate into a rinse water pipe, it was the practice to drill and thread two holes in the rinse water pipe, the iirst for receiving a fitting connected to a pressure-responsive switch for the pump motor, and the second for receiving a tting connected to the pump delivery line. In some such systems, a small check valve was installed in the second fitting to prevent water from backing up onto the delivery line. One of the major problems encountered in the operation of the prior art systems was in obtaining complete diffusion, or admixing, of the concentrate in the rinse water. The piston type pumps, which are conventionally used because they are economical and relatively easy to service, having a pulsating output which results in the introduction of a series of slugs of the concentrate into the rinse water with the result that the mixture of rinse water and concentrate is not uniform. Also, the rinse-aid concentrate would congeal and gumup the small outlet passage of the pump delivery iitting so that after the prior art apparatus had been in operation for a while, the operator could never be sure as to how much of the concentrate actually entered the rinse water stream. Furthermore, drilling and tapping the extra hole for the pressure-responsive switch was an extra expense and a nuisance.

The object now is to provide a single tting for both the pump delivery line and the pressure-responsive pump switch, and to provide in the tting an inlet passage for receiving a small stream of water from the rinse water line, a ram surface exposed to the stream of rinse water so that the rinse water will be forced into the inlet passage by a ram effect, a mixing chamber communicating with the water inlet passage, an outlet leading from the mixing chamber back into the rinse water pipe, and a duct leading from the mixing chamber to a fluid connection for the pressure-responsive pump switch. In accordance with these objectives, it is proposed now to take off a small quantity of the rinse water and mix it with the rinse-aid concentrate before the latter is introduced into the wash-water stream, and to simultaneousiy utilize the pressure prevailing in the mixing chamber for actuating the pump switch. The fuliillment of these objectives results in the complete admixture of the rinse-aid concentrate into the rinse water stream, the de-gumming of the outlet passage through which concentrate is introduced into the rinse water stream and the elimination of the necessity for drilling and tapping one of the holes in the rinse water pipe.

These and other objects will be apparent from the following speciiication and drawings, in which:

FIG. l is a vertical section through the subject device, shown in typical use on a rinse water pipe, an associated pressure-responsive pump switch, switch leads, pump,

pump delivery line and fitting, and concentrate reservoir being shown in broken lines;

FIG. 2 is a front View of the device per se; and

FIG. 3 is a rear view of the device per se.

Referring now to the drawings in which like reference numerals denote similar elements, FIG. 1 shows the diffuser in typical installation in the rinse water supply pipe 2 of a commercial dishwasher, wherein the water flows in the direction indicated by the arrow. The purpose of the diffuser is to admix a concentrated rinseaid solution, supplied from a reservoir 4 by a piston pump 6 through a delivery line 8 to the diffuser, into the flowing stream of rinse water whenever the rinse water control valve, not shown, is turned on. The desired ratio of rinse-aid solution to rinse water may be on the order of one part to 20,000 parts or even one part to 2,000 parts, depending upon the strength of the rinse-aid solution and the characteristics of the water. Pump 6 is conventionally driven by an electric motor energized through a pressure responsive switch 10 and leads 12 so that whenever pressure is developed by ilow rinse water in the supply pipe 2, switch l0 is closed. The illustrated elements are on the down stream side of the rinse water control valve so that when the latter is closed, no appreciable pressure prevails in supply pipe 2 and hence switch l0 opens to shut off the pump. Heretofore, switch l0 was independently mounted in supply pipe 2 by drilling and tapping a hole in the pipe a short distance upstream from the hole through which the concentrate was introduced. Since reservoir 4, pump 6, delivery line 8, pressure responsive switch 10 and leads 12 are conventional elements well known in the art, they have been illustrated diagrammatically and in broken lines.

The invention is concerned with the diffuser i4 whose body encloses a mixing chamber lr6, the walls of which are cylindrical and tapped as at 17 to receive a coupling 18 for the pump delivery line 8. Dituser 14 has an outwardly projecting nipple 19 which is threaded, at 20 for screwing into a tapped opening through the wall of pipe 2, When thusly mounted, nipple 19 has an end portion 22 which projects into the interior of pipe 2 so as to inter- "cept the stream of rinse water liowing therethrough. A

restricted outlet passage 23 through the lower portion of nipple i9 connects mixing chamber 16 with the interior of pipe 2. As shown in FlGS. l and 2, the upper side of inner end portion 22 is hollowed out so as to present upwardly concave ram surface 24 against which the ilowing water impinges. A restricted inlet passage 2d, or ram hole, at the inner end of the ram surface connects the concavity embraced by the ram surface 24 with diifusion chamber l5.

Above mixing chamber 16 and separated therefrom by a Wall 2S is a pressure chamber 30, the pressure chamber being connected to mixing chamber 16 by a duct 32 through wall ZS. The rear end of pressure chamber 30 is tapped as at 34 to receive the threaded coupling 36 of pressure responsive switch l0.

The operation is as follows: When rinse water ows in pipe 2, it impinges against the concave ram surface 24 and a certain amount of the rinse water is driven through ram hole 26 into diffusion chamber 16 by the ram effect of the water impinging against surface 24. The amount of water driven through ram hole 26 for a given pressure of water flowing in pipe 2 depends in large part upon the size of the ram hole, and the size of the passage is selected according to the delivery of the particular pump utilized in the system. For example, with the pump running at 70 strokes per minutes, delivering about 8 cc. per minute, a ram hole oi 1&2 diameter was found to obtain the proper mixture of rinse-aid concentrate to Water. In another example Where the pump was run at 160 strokes per minute, delivering about 2O cc. per minute, a ram hole of 1/16" diameter was found to obtain the proper mixture. in both examples, the outlet passage 23 was V10 in diameter. When water fiows into mixing chamber 16 through ram hole 26, sufficient pressure develops in pressure chamber 3d so as to close switch l@ and energize pump 6, whereupon the latter forces rinseaid concentrate via delivery tube 8 into mixing chamber 16 where the rinse-aid concentrate mixes with tl e water which has entered ram hole 26. The pulsations of the piston pump 6 assist in the mixture of the concentrate with the rinse water that has entered through ram hole 26, There is a suficient differential in the pressure prevailing at the inner end of ram hole 26, as compared with the pressure at the inner end of restricted outlet passage 23 so that the premixed water and rinse-aid concentrate exhausts through outlet passage 23 into the lay-flowing stream of rinse water. The water entering through ram hole 26 dilutes the rinse-aid concentrate and this, plus the circulation, keeps the passages free of gummy or congealed concentrate.

The diffuser is operable also in conjunction with a hand pump, in which case the rear end of pressure chamber 3f) is closed by plug. Also, it is operable to mix other solutions, such as detergents, soaps and sterilizing concentrates into a stream of water flowing in a pipe.

The invention is not limited to the details illustrated and described herein, but is intended to cover all substitutions, modifications and equivalents within the scope of the following claims.

I claim:

l. A device for introducing a solution into a stream of water flowing in one direction through a pipe, comprising a hollow body enclosing a mixing chamber, means for connecting said mixing chamber to a source of said solution, a nipple connected to said body and having an inner end adapted to project into the interior of said pipe through an opening in the wall thereof, said nipple having a ram surface thereon extending inwardly from the inner end thereof and adapted to be disposed contra to the direction of fiow of water in the pipe, inlet conduit means leading through said nipple from the ram surface to said mixing chamber, and outlet conduit means leading from said mixing chamber through said nipple to the inner end thereof.

2. The combination claimed in claim 1, said ram surface being concave.

3. The combination claimed in claim 2, said inlet conduit means leading from the inner end of said ram surface.

4. A device for introducing a solution supplied by an electric motor actuated pump having a pressure sensitive switch into a stream of water flowing in one direction through a pipe, comprising a hollow body enclosing a mixing chamber, means for connecting said mixing chamber to the delivery side of said pump, means for connecting said mixing chamber to the pressure sensitive switch for closing the latter in response to pressure prevailing in the mixing chamber, a nipple connected to said body and having an inner end adapted to project into the interior of said pipe through an opening in the Wall thereof, said nipple having a ram surface thereon extending inwardly from the inner end thereof and adapted to be disposed contra to the direction of fiow of water in the pipe, conduit means leading through said nipple from the inner end of said ram surface to said mixing chamber, and outlet conduit means leading from said mixing chamber to the inner end of said nipple.

5. A device for introducing a solution supplied by an electric motor actuated pump having a pressure sensitive switch into a stream of water flowing in one direction through a pipe, comprising a hollow body enclosing a mixing chamber, and a pressure chamber, means for connecting said mixing chamber to the delivery side of said pump, means for connecting said pressure chamber to the pressure sensitive switch for closing the latter in response to pressure prevailing in the mixing chamber, conduit means connecting the mixing chamber to the pressure chamber, a nipple connected to said body and having an inner end adapted to propect into the interior of said pipe through an opening in the Wall thereof, said nipple having a ram surface thereon extending inwardly from the inner end thereof and adapted to be disposed contra to the direction of fiow of water in the pipe, conduit means leading through said nipple from the inner end of said ram surface to said mixing chamber, and outlet conduit means leading from said mixing chamber to the inner end of said nipple.

6. The combination claimed in claim 5, said ram surface being concave.

7. A device for introducing a solution into a stream of water fiowing through a pipe, comprising a hollow body defining a mixing chamber; a nipple rigid with said body and projecting outwardly therefrom and adapted to extend into the interior of the pipe through a hole in the side thereof, said nipple having a hollow inner end communicating with said mixing chamber, a concave ram surface extending inwardly from the outer end on one side thereof, a first passage extending from the inner end of the ram surface to the hollow inner end of the nipple, and a second passage extending from the outer end to the hollow inner end thereof; and coupling means whereby the mixing chamber may be connected to a source of supply of the solution.

8. The combination claimed in claim 7, said hollow body also defining a pressure chamber separated by a common wall from the mixing chamber, said wall having a duct therethrough connecting the pressure chamber with the mixing chamber, and coupling means whereby said pressure chamber may be connected to pressure-sensitive switch for controlling the supply of the solution.

No references cited. 

1. A DEVICE FOR INTRODUCING A SOLUTION INTO A STREAM OF WATER FLOWING IN ONE DIRECTION THROUGH A PIPE, COMPRISING A HOLLOW BODY ENCLOSING A MIXING CHAMBER, MEANS FOR CONNECTING SAID MIXING CHAMBER TO A SOURCE OF SAID SOLUTION, A NIPPLE CONNECTED TO SAID BODY AND HAVING AN INNER END ADAPTED TO PROJECT INTO THE INTERIOR OF SAID PIPE THROUGH AN OPENING IN THE WALL THEREOF, SAID NIPPLE HAVING A RAM SURFACE THEREON EXTENDING INWARDLY FROM THE INNER END THEREOF AND ADAPTED TO BE DISPOSED CONTRA 